JP2003200527A - Metal foil laminate and double-side metal foil laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal foil laminate excellent in interlaminar adhesion, dynamic strength and heat resistance and reduced in curling. <P>SOLUTION: The metal foil laminate is obtained by casting a silane modified polyimide resin composition (A), which contains an alkoxy group-containing silane modified polyimide (a) obtained by reacting polyamic acid (1) and/or polyimide (2) with an epoxy group-containing alkoxysilane partial condensate (3) and a polar solvent, on a metal foil. The metal foil laminate is obtained by casting a silane modified polyimide resin composition (B), which contains the alkoxy group-containing silane modified polyimide (a) obtained by reacting polyamic acid (1) and/or polyimide (2) with the epoxy group-containing alkoxysilane partial condensate (3), the polar solvent (b) and an inorganic filler (c), on the metal foil. A double-side metal foil laminate is obtained by plating the polyimide resin side of the metal foil laminate. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a metal foil laminate obtained by casting a silane-modified polyimide resin composition (A) containing an alkoxy group-containing silane-modified polyimide (a) and a polar solvent (b) on a copper foil. Regarding the body The metal foil laminate can be used as a flexible printed board (FPC) or tape automated bonding (TAB).

[0002]

2. Description of the Related Art In recent years, with the miniaturization of internal parts accompanying the miniaturization of electric appliances and electronic devices, there has been a demand for miniaturization and high density of circuit boards used for electric appliances and electronic devices. In order to realize the miniaturization of the circuit, it is necessary to use a material that is inexpensive and has excellent physical properties such as electrical properties. A polyimide film that has excellent heat resistance and electrical properties and is flexible is a flexible printed board ( It has come to be widely used as FPC) and tape automated bonding (TAB).

At present, polyimide films are used for flexible printed circuit boards (FPC) and tape automated tapes.
Since it is used as a substrate material for bonding (TAB) and the like, a method of laminating it with a copper foil using an adhesive such as an epoxy resin has been adopted, but since the heat resistance of the adhesive is inferior, the original characteristics of polyimide are used. Has not been able to fully exert.

Therefore, a polyimide base material obtained by applying a polyamic acid solution to a copper foil, drying and imidizing it, or thermocompressing a thermoplastic polyimide without using an adhesive having poor heat resistance has been studied. However, since the polyimide copper foil laminate obtained by this method has a low adhesive strength, it is difficult to use it for copper foil with a small number of irregularities (small surface roughness) required for fine pitch and high frequency compatibility. In addition, there is a problem that the heat resistance is impaired.

In addition, “Polymer Papers”, Volume 57, No. As described in p. 233, published in 2000, when polyamic acid is directly applied to a copper foil as a base material, migration of copper ions easily occurs in the polyimide near the interface of the copper foil, resulting in insulation properties. Has the disadvantage of decreasing. In order to secure sufficient insulation, a thicker imide layer may be used, but under the present circumstances where the density and integration of electronic circuits are rapidly increasing, increasing the thickness is unacceptable. Therefore, there is a demand for technological development of a metal foil laminate capable of highly suppressing migration of copper ions in a thin film.

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the above problems and provides a metal foil laminate having excellent adhesion to a copper foil with less unevenness and less migration of copper ions without using an adhesive. The purpose is to provide.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted investigations to solve the above-mentioned problems, and found that a metal foil laminate obtained by casting a specific alkoxy group-containing silane-modified polyimide on a copper foil. It has been found that the above problems can be solved by using them.

That is, according to the present invention, an alkoxy group-containing silane-modified polyimide (a) obtained by reacting a polyamic acid (1) and / or a polyimide (2) with an epoxy group-containing alkoxysilane partial condensate (3), And a metal foil laminate obtained by casting a silane-modified polyimide resin composition (A) containing a polar solvent (b) on a copper foil; polyamic acid (1) and / or polyimide (2).
And an epoxy group-containing alkoxysilane partial condensate (3)
Alkoxy group-containing silane-modified polyimide (a), polar solvent (b) and inorganic filler (c)
A metal foil laminate obtained by casting a silane-modified polyimide resin composition (B) containing on a metal foil; a polyamic acid (1) and / or a polyimide (2), and an epoxy group-containing alkoxysilane partial condensate ( 3) The silane-modified polyimide resin composition (A) containing the alkoxy group-containing silane-modified polyimide (a) and the polar solvent (b) obtained by reacting with 3) is cast on a metal foil, and then the linear expansion coefficient is 25 ppm. A metal foil laminate obtained by casting a resin composition containing a polyimide polymer for forming the following film and a polar solvent (b); a polyamic acid (1) and / or a polyimide (2), and an epoxy group-containing alkoxysilane. Contains an alkoxy group-containing silane-modified polyimide (a) obtained by reacting with a partial condensate (3) and a polar solvent (b) A metal foil laminate obtained by casting the silane-modified polyimide resin composition (A) on a metal foil, and then casting the silane-modified polyimide resin composition (A) that forms a cured film having a linear expansion coefficient of 25 ppm or less. A double-sided metal foil laminate obtained by plating the polyimide resin side of the metal foil laminate.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Polyamic acid (1) which constitutes an alkoxy group-containing silane-modified polyimide composition of the present invention
As a resin having a carboxyl group whose main chain is formed by an amide bond and which can react with the amide bond to form an imide bond, for example, tetracarboxylic acids and diamines in a polar solvent, usually -20 A polyamic acid solution obtained by reacting at 60 ° C to 60 ° C can be used. The polyimide (2) is a polymer having an imide group in the molecule, and for example, the polyamic acid solution may be 80
A polyimide solution obtained by a dehydration ring-closing reaction at ˜160 ° C. can be used. The polyamic acid (1) also includes those obtained by imidizing a part of the polyamic acid (1) by dehydration ring closure. The molecular weight of the polyamic acid (1) and / or the polyimide (2) is not particularly limited, but the number average molecular weight is 3000 to 5000.
It is preferably about 0.

Examples of the above-mentioned tetracarboxylic acids include pyromellitic acid anhydride, 1,23,4-benzenetetracarboxylic acid anhydride, 1,4,5,8-naphthalenetetracarboxylic acid anhydride, and 2,3. , 6,7-Naphthalenetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 2, 3, 3 ',
4'-biphenyltetracarboxylic dianhydride, 3,
3 ', 4,4'-benzophenone tetracarboxylic acid dianhydride, 2,3,3', 4'-benzophenone tetracarboxylic acid dianhydride, 3,3 ', 4,4'-diphenyl ether tetracarboxylic acid dianhydride Things, 2, 3, 3 ', 4'-
Diphenyl ether tetracarboxylic dianhydride, 3,
3 ', 4,4'-diphenylsulfone tetracarboxylic dianhydride, 2,3,3', 4'-diphenylsulfone tetracarboxylic dianhydride, 2,2-bis (3,3 ',
4,4'-Tetracarboxyphenyl) tetrafluoropropane dianhydride, 2,2'-bis (3,4-dicarboxyphenoxyphenyl) sulfone dianhydride, 2,2-
Bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, cyclopentanetetracarboxylic acid anhydride, butane-1,2,3, 4-tetracarboxylic acid, 2,
3,5-tricarboxycyclopentyl acetic acid anhydride, etc. can be exemplified, and these can be used alone or in combination with 2
Used in combination of two or more species.

Further, within the range of not losing the effects of the present invention, tricarboxylic acids such as trimellitic anhydride, butane-1,2,4-tricarboxylic acid and naphthalene-1,2,4-tricarboxylic acid, oxalic acid, Malonic acid, succinic acid, glutaric acid, adipic acid, vimelic acid, suberic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid and other aliphatic dicarboxylic acids and their acid anhydrides, isophthalic acid, terephthalic acid, Aromatic dicarboxylic acids such as diphenylmethane-4,4'-dicarboxylic acid and their acid anhydrides can be used in combination. However, if the ratio of these to the tetracarboxylic acid is too large, the insulating property and heat resistance of the obtained cured product tend to deteriorate, so the amount used is usually 30 mol% or less relative to the tetracarboxylic acid. Is preferred.

Examples of the above diamines are 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminophenylmethane,
3,3'-dimethyl-4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, 4,
4'-di (m-aminophenoxy) diphenyl sulfone, 4,4'-diaminodiphenyl sulfide, 1,4
-Diaminobenzene, 2,5-diaminotoluene, isophoronediamine, 4- (2-aminophenoxy) -1,
3-diaminobenzene, 4- (4-aminophenoxy)
-1,3-diaminobenzene, 2-amino-4- (4-
Aminophenyl) thiazole, 2-amino-4-phenyl-5- (4-aminophenyl) thiazole, benzidine, 3,3 ′, 5,5′-tetramethylbenzidine, octafluorobenzidine, o-tolidine, m-tolidine. , P-phenylenediamine, m-phenylenediamine, 1,2-bis (anilino) ethane, 2,2-bis (p-aminophenyl) propane, 2,2-bis (p-
Aminophenyl) hexafluoropropane, 2,6-diaminonaphthalene, diaminobenzotrifluoride,
1,4-bis (p-aminophenoxy) benzene, 4,
4'-bis (p-aminophenoxy) biphenyl, diaminoanthraquinone, 1,3-bis (anilino) hexafluoropropane, 1,4-bis (anilino) octafluoropropane, 2,2-bis [4- (p- Aminophenoxy) phenyl] hexafluoropropane and the like can be exemplified, and these are used alone or in combination of two or more.

The above tetracarboxylic acids and the above diamines are represented by the following formula: (moles of tetracarboxylic acids) / (moles of diamines) = (0.5 to 0.8) / (1.2 to 2.0) It is also possible to use a polyimide adduct having a carboxylic acid anhydride group or an amino group at the molecular end obtained by the reaction within the range.

The polyamic acid (1) and / or the polyimide (2) contains the above-mentioned tetracarboxylic acids and diamines,
(Moles of tetracarboxylic acids / moles of diamines)
= 0.9 to 1.1, and is obtained through the polyamic acid solution reacted in the polar solvent (b). As the polar solvent (b), the generated polyamic acid (1) and / or
Alternatively, the kind and the amount used are not particularly limited as long as they can dissolve the polyimide (2), but N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, cresol, dimethylsulfoxide, N-methylcaprolactam, methyltriglyme. It is preferable to use a polar solvent such as methyl diglyme or benzyl alcohol so that the solid residue in terms of polyimide becomes 5 to 40%. Here, the polyimide-reduced solid residue represents the weight% of the polyimide with respect to the solution when the polyamic acid (1) and / or the polyimide (2) is completely cured into the polyimide. If the solid residue in terms of polyimide is less than 5%, the production cost of the polyamic acid (1) and / or polyimide (2) solution will be high. On the other hand, when it exceeds 40%, the polyamic acid (1) and / or the polyimide (2) solution has a high viscosity at room temperature, so that the handling tends to be poor.
The reaction temperature of the polyamic acid is not particularly limited,
It is preferable to adjust the temperature to 20 to 60 ° C.

The polyimide (2) is obtained by dehydration ring closure of the above polyamic acid (1). 6 for dehydration ring closure
The heating is performed at a temperature of 0 to 150 ° C. Further, this dehydration ring-closing reaction may use a dehydrating agent and a catalytic amount of a tertiary amine. Examples of the dehydrating agent here include aliphatic acid anhydrides such as acetic anhydride, aromatic acid anhydrides, and the like. Examples of the catalyst include aliphatic tertiary amines such as triethylamine, aromatic tertiary amines such as dimethylaniline, and heterocyclic tertiary amines such as pyridine, picoline, and isoquinoline.

The polyamic acid (1) used in the present invention can be formed into a film by causing a dehydration ring closure reaction to partially imidize the polyamic acid (1) solution unless turbidity or precipitation occurs in the solution. Curing shrinkage is reduced,
It is preferable because curl can be prevented. However, if turbidity or precipitation occurs in the solution due to excessive progress of the dehydration ring-closing reaction, the reaction with the epoxy group-containing alkoxysilane partial condensate (3) will not proceed, and thus the desired alkoxy group-containing silane modification The polyimide (A) cannot be obtained. In the polyimide (2), the ratio of the imide groups produced when turbidity or precipitation occurs depends on the type of tetracarboxylic acid or diamine and the type of solvent.

The epoxy group-containing alkoxysilane partial condensate (3) used in the present invention is a compound obtained by removing an epoxy compound having one hydroxyl group in a molecule (hereinafter simply referred to as an epoxy compound) and an alkoxysilane partial condensate. It is obtained by an alcohol reaction and is disclosed in JP-A-2001-11.
It is synthesized by the method described in Japanese Patent No. 4894.

As the epoxy compound, the number of epoxy groups is not particularly limited as long as it is an epoxy compound having one hydroxyl group in one molecule. Further, as the epoxy compound, the one having a carbon number of 15 or less is preferable because the smaller the molecular weight, the better the compatibility with the alkoxysilane partial condensate and the higher the effect of imparting heat resistance and adhesion.
As a specific example thereof, monoglycidyl ethers having one hydroxyl group at the molecular end obtained by reacting epichlorohydrin with water, dihydric alcohol or phenols having two hydroxyl groups; epichlorohydrin and Polyglycidyl ethers having one hydroxyl group at the molecular end obtained by reacting a trihydric or higher polyhydric alcohol such as glycerin or pentaerythritol; a molecular end obtained by reacting epichlorohydrin and aminomonoalcohol Examples thereof include an epoxy compound having one hydroxyl group; and an alicyclic hydrocarbon monoepoxide having one hydroxyl group in the molecule (for example, epoxidized tetrahydrobenzyl alcohol). Among these epoxy compounds, glycidol is the most excellent in the heat resistance imparting effect, and is also most suitable because it has high reactivity with the alkoxysilane partial condensate.

As the alkoxysilane partial condensate, General formula (1): R¹ _mSi (OR²)_(4-m) (In the formula, m represents an integer of 0 or 1, and R¹Is carbon number 8 or more
Lower alkyl or aryl group, R²Is carbon number 4 or less
Is a lower alkyl group. ) Hydrolyzable Al
Coxysilane monomer, acid or base catalyst, and water
Hydrolyzed in the presence of and partially condensed
Is used.

Specific examples of the hydrolyzable alkoxysilane monomer which is a constituent raw material of the alkoxysilane partial condensate include tetramethoxysilane, tetraethoxysilane,
Tetraalkoxysilanes such as tetrapropoxysilane and tetraisopropoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane. Examples thereof include trialkoxysilanes such as silane, n-propyltriethoxysilane, isopropyltrimethoxysilane, and isopropyltriethoxysilane. Usually, among these, particularly, since the alkoxysilane partial condensate (B) has a high reactivity with glycidol, a compound synthesized by using 70 mol% or more of tetramethoxysilane or methyltrimethoxysilane is preferable.

The number average molecular weight of the alkoxysilane partial condensate is preferably about 230 to 2000, and the average number of Si in one molecule is preferably about 2 to 11.

The ratio of the epoxy compound and the alkoxysilane partial condensate to be used is not particularly limited as long as the alkoxy group substantially remains, but in the resulting epoxy group-containing alkoxysilane partial condensate (3). The ratio of the epoxy group of is usually the equivalent of the hydroxyl group of the epoxy compound / the equivalent of the alkoxyl group of the alkoxysilane condensate =
It is preferable that the alkoxysilane condensate (B) and the epoxy compound are dealcoholized at a charging ratio of 0.01 / 1 to 0.5 / 1.

The reaction of the alkoxysilane partial condensate with the epoxy compound is carried out by, for example, charging the above-mentioned respective components and distilling off the alcohol produced by heating to carry out a dealcoholization reaction. The reaction temperature is about 50 to 150 ° C., preferably 70 to 110 ° C., and the total reaction time is about 1 to 15 hours.

The alkoxy group-containing silane-modified polyimide of the present invention is obtained by reacting the polyamic acid (1) and / or the polyimide (2) with the epoxy group-containing alkoxysilane partial condensate (3). The use ratio of the polyamic acid (1) and / or the polyimide (2) and the epoxy group-containing alkoxysilane partial condensate (3) is not particularly limited, but (of the epoxy group of the epoxy group-containing alkoxysilane partial condensate (3) Equivalent) / (equivalent of carboxylic acid group of tetracarboxylic acid used in polyamic acid (1) and / or polyimide (2)) is 0.01 to 0.3
The range is preferably If the above numerical value is less than 0.01, it is difficult to obtain adhesion to the metal foil, and if it exceeds 0.3, the metal foil laminate becomes brittle, which is not preferable.

The production of the alkoxy group-containing silane-modified polyimide (a) is carried out, for example, by charging the above-mentioned components,
The reaction is carried out by heating in a substantially anhydrous state. This reaction is carried out with a carboxylic acid group of polyamic acid (1) or a carboxylic acid anhydride group or an amino group at the molecular end of polyimide (2),
Epoxy group-containing alkoxysilane partial condensate (3)
The main purpose of this reaction is to react the epoxy group of the epoxy group. During this reaction, silica is formed by the sol-gel reaction of the alkoxysilyl moiety of the epoxy group-containing alkoxysilane partial condensate (3), and the ring closure reaction of the polyamic acid to the imide group. Need to be suppressed. Therefore, the reaction temperature is about 50 to 120 ° C., preferably 60 to 100 ° C., and the total reaction time is 1 to 30.
It is preferable to perform it for about an hour.

Further, in the dealcoholization reaction, a catalyst which is conventionally used for reacting an epoxy group with a carboxylic acid can be used to accelerate the reaction. 1,8-diaza-bicyclo [5,4,0] -7-
Tertiary amines such as undecene, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol; 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, Imidazoles such as 2-heptadecyl imidazole and benzimidazole; organic phosphines such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine and phenylphosphine; tetraphenylphosphonium tetraphenylborate, 2-ethyl-4-methyl Imidazole tetraphenylborate, N-methylmorpholine
Examples thereof include tetraphenylboron salts such as tetraphenylborate. The reaction catalyst was 0.1% by weight based on 100 parts by weight of the solid residue of polyamic acid in terms of polyimide.
It is preferably used in a proportion of 01 to 5 parts by weight.

The above reaction is preferably carried out in the polar solvent (b). The polar solvent (b) is not particularly limited as long as it can dissolve the polyamic acid (1) and / or the polyimide (2) and the epoxy group-containing alkoxysilane partial condensate (3). Examples of such a solvent include those used at the time of producing the polyamic acid (1).

Alkoxy group-containing silane thus obtained
Sila containing modified polyimide (a) and polar solvent (b)
The modified polyimide resin composition (A) has an
It has an alkoxy group derived from the partial condensate of lucoxysilane.
is doing. The content of the alkoxy group is not particularly limited.
However, this alkoxy group does not evaporate the polar solvent (b) or
Heat treatment or reaction with moisture (humidity)
They were bound to each other by the Rugel reaction or dealcohol condensation.
Since it is necessary to form a cured product, an alkoxy group
The silane-containing polyimide (a) containing is usually an alkoxysilane.
50 to 95 mol of the alkoxy group of the partial condensate of orchid (3)
%, Preferably 60-90 mol% unreacted
It is good to do it. Modification of silane containing such alkoxy groups
The cured product obtained from polyimide is General formula (2): R¹ _mSiO_{(4-m) / 2} (In the formula, m represents an integer of 0 or 1, and R¹Is carbon number 8 or more
The lower alkyl group or aryl group is shown. )
Gelled fine silica sites (higher-order network of siloxane bonds
Is a polyimide-silica hybrid having an eye structure)
It Further, the alkoxy group-containing silane-modified polyimid of the present invention
Is polyamic acid (1) and / or polyimide
The main component of (2) is silane-modified.
Mitsui alkoxy group-containing silane-modified polyimide resin composition
Unreacted polyamic acid (1) and / or polyimide
Mido (2), alkoxysilane partial condensate, epoxy group
Containing alkoxysilane partial condensate (3), used in the reaction
It may contain a solvent or a catalyst. In addition, unreacted
Alkoxysilane partial condensate, epoxy group-containing alkoxy
Silane partial condensate (3) undergoes hydrolysis and polycondensation during curing.
The silica cures when combined with the alkoxy group-containing silane-modified
Polyimide-silica hybrid, integrated with Liimide
Becomes

For the purpose of suppressing curling of the metal foil laminate,
A conventionally known inorganic filler (c) may be added to the alkoxy group-containing silane-modified polyimide resin composition of the present invention. As the inorganic filler, oxides such as silica, alumina, titania and magnesium oxide, complex oxides such as kaolin, talc and montmorillonite, carbonates such as calcium carbonate and barium carbonate, sulfates such as calcium sulfate and barium sulfate, titanium. Barium acid, titanates such as potassium titanate, and phosphates such as tricalcium phosphate, dicalcium phosphate, and monocalcium phosphate can be used, but are not limited thereto. . Among these inorganic fillers (c), silica is most preferably used in consideration of the stability of the alkoxy group-containing silane-modified polyimide resin composition (B), the dispersibility of the inorganic filler, and the curl suppressing effect.

Usually, the average particle diameter of the inorganic filler (c) is preferably 0.01 μm or more and 5 μm or less. Further, the blending amount is preferably in the range of 50% by weight or less based on the resin content of the silane-modified polyimide resin composition (B). The method of adding these particles is not particularly limited as long as it is a stage until a film is formed using the silane-modified polyimide resin composition (B). For example, polyamic acid (1) and / or polyimide ( It may be added at the polymerization stage of 2) or by reaction with the epoxy group-containing alkoxysilane partial condensate (3), or may be added at the time of film formation.

Further, in addition to the silane-modified polyimide resin composition (A) or (B), an organic solvent may be added to the silane-modified polyimide resin composition (A) or (B), if necessary for various purposes, as long as the effects of the present invention are not impaired.
Plasticizers, weathering agents, antioxidants, heat stabilizers, lubricants, antistatic agents, brighteners, colorants, conductive agents release agents, surface treatment agents, viscosity modifiers, coupling agents, etc. Good.

Examples of the metal foil used in the metal foil laminate include electrolytic copper foil, rolled copper foil, aluminum foil, stainless steel foil and the like. Among these, electrolytic copper foil and rolled copper foil are preferable because they have excellent conductivity, heat resistance, and mechanical strength. Generally, for FPC and TAB, a surface-treated copper foil having an increased surface roughness of the adhesive surface of the copper foil is used for the purpose of obtaining adhesion with an adhesive, but obtained from the silane-modified polyimide resin composition. The cast film obtained has excellent adhesion to metal foil without the use of an adhesive, and there is no need for surface roughening. Untreated copper foil, fine pitch, and high-frequency roughness Sufficient adhesion can be obtained even with low copper foil. As the metal foil, one having a surface roughness (Rz) that is not so large is preferable, and specifically, a copper foil having Rz of 7 μm or less, particularly 3 μm or less is preferably used. The thickness of the metal foil is not particularly limited, but 70 μm or less, particularly 3 to 35 μm.
It is preferably m.

The metal foil laminate of the present invention can be obtained by casting the silane-modified polyimide resin composition (A) or (B) on a metal foil by a known method. It is preferable to dry and cure the cast film in two stages. The curing temperature and time are appropriately determined depending on the amount of dehydration ring closure of the used polyimide (1) and / or polyamic acid (2) and the type of solvent. The first stage is preferably performed at 80 to 150 ° C. for 3 to 30 minutes mainly for the purpose of drying. Then, the residual solvent is completely removed at 200 to 500 ° C. for 1 to 40 minutes to completely ring-close the imide. At this time, it is preferable to remove volatile matter up to 50% by weight or less based on the completely cured polyimide film in the first drying step. The reason is that if a volatile content exceeding 50% by weight occurs in the second curing step, the cured film contracts and cracks, which is not preferable. At this time, a solvent, alcohol, and water are generated as volatile components.

The above-mentioned metal laminate has high adhesion strength between metal foil / cured film and high reliability, but tetracarboxylic acids, diamines, and alkoxysilane moieties constituting the alkoxy group-containing silane-modified polyimide resin composition (A). Depending on the type of the condensate (3), the coefficient of linear expansion is different from that of the copper foil, so that the metal foil may curl and the smoothness may be lost. In such a case, it is possible to solve it by the following method.

Inorganic filler (c) for the alkoxy group-containing silane-modified polyimide (a) and polar solvent (b)
And a silane-modified polyimide resin composition (B) is prepared and cast to obtain a cured polyimide film having a linear expansion coefficient of 25 ppm or less, preferably 5 to 20 pp.
It can be solved by adjusting to m. The amount of the inorganic filler (c) used at this time varies depending on the type of the alkoxy group-containing silane-modified polyimide, but if the flexibility of the cured film is taken into consideration, the inorganic filler (c) is added at 50% by weight or less based on the cured film. It is preferable to use.

The cured film has a linear expansion coefficient of 25 pp.
Even if the silane-modified polyimide resin composition exceeds m, if the film thickness is 10 μm or less, curling does not occur and can be solved by reducing the film thickness.

On the surface on which the silane-modified polyimide resin composition is cast, a conventionally known linear expansion coefficient is 25 pp.
It is also possible to solve the curl by coating a polyimide of m or less to form a three-layer structure of metal foil / polyimide-silica hybrid / polyimide. At this time, the film curing method is not particularly limited. For example, after casting the silane-modified polyimide resin composition on a metal foil, a film is formed under the curing conditions under the second-stage curing conditions, and then a polyimide having a low linear expansion is cast. However, it may be cured. Also, after casting the silane-modified polyimide resin composition on the metal foil, only the first step of the drying step is performed to cast the low linear expansion polyimide, and after the drying step, both layers are subjected to the second step conditions. It may be cured with.

Instead of the above-mentioned conventionally known low linear expansion polyimide, a silane-modified polyimide resin composition having a linear expansion coefficient of a cured film of 25 ppm or less by using an inorganic filler (c) is used. Polyimide
-Silica hybrid / low linear expansion polyimide-silica hybrid may be used.

The thickness of these cured films may be appropriately determined depending on the application, but when used for FPC and TAB, it is 3 to 10 as the polyimide portion excluding the copper foil.
0 μm, particularly 5 to 50 μm is preferable.

Further, a double-sided metal foil laminate can be obtained by plating the polyimide side of the metal foil laminate having a metal foil adhered on one side thereof. As a method for filling the metal plating, electroless plating method, combined use of electroless plating method and electrolytic plating method, pulse plating method, heat melting method,
Although a known method such as a plasma method or a sputtering method can be adopted, an electroless plating method or a combination of electroless plating and electrolytic plating is particularly preferable from the viewpoint of mass productivity. Incidentally, in the electroless plating method, a metal serving as a catalyst is deposited on the surface and inner wall of the base material, and then copper or the like is deposited by the electroless plating method for plating. The combined method of electroless plating and electrolytic plating is to deposit electroless plating thinly, and then to plate metal by thickening it by electrolytic plating. In the present invention, the plating metal is not particularly limited, and examples thereof include copper, nickel, gold, silver, platinum, tin, lead, cobalt, tungsten, molybdenum, palladium and alloys thereof. Of these, copper is particularly preferable.

[0041]

When the silane-modified polyimide resin composition using the alkoxy-group-containing silane-modified polyimide of the present invention is used, it is excellent in interlayer adhesion, mechanical strength and heat resistance, and has less curling and copper ion migration. A laminated body can be manufactured.

[0042]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples.

Synthesis Example 1 (Production of Epoxy Group-Containing Alkoxysilane Partial Condensate (3)) Glycidol (manufactured by NOF Corporation) Product name "Epiol OH") 1
400 g and tetramethoxysilane partial condensate (manufactured by Tama Chemical Co., Ltd., trade name “methyl silicate 51”, Si
The average number of 4) was 8957.9 g, and the mixture was heated to 90 ° C. with stirring under a nitrogen stream, and 2.0 g of dibutyltin dilaurate as a catalyst was added and reacted. During the reaction, the produced methanol was distilled off using a water separator, and when the amount reached about 630 g, the mixture was cooled. The time required for cooling after the temperature was raised was 5 hours. Then, 13kP
About 80 g of methanol remaining in the system was removed under reduced pressure at a for about 10 minutes. Thus, an epoxy group-containing alkoxysilane partial condensate (3A) was obtained. The equivalent of the hydroxyl group of the epoxy compound at the time of charging / the equivalent of the alkoxyl group of the alkoxysilane condensate (B) (equivalent ratio) = 0.1
0, the epoxy equivalent is 512 g / eq.

Synthetic Example 2 (Production of Epoxy Group-Containing Alkoxysilane Partial Condensate (3)) In the same reactor as in Synthetic Example 1, 1400 g of glycidol and methyltrimethoxysilane partial condensate (manufactured by Tama Chemical Co., Ltd., product Name "MT
MS-B ”, the average number of Si was 6) 9142.1 g was charged, and the temperature was raised to 90 ° C. with stirring under a nitrogen stream, and 2.0 g of dibutyltin dilaurate as a catalyst was added and reacted. During the reaction, the produced methanol was distilled off using a water separator, and when the amount reached about 640 g, the mixture was cooled. The time required for cooling after raising the temperature was 6.5 hours. Then, about 32 g of methanol remaining in the system was removed under reduced pressure at 13 kPa for about 10 minutes. Thus, the epoxy group-containing alkoxysilane partial condensate (3
B) was obtained. The equivalent of the hydroxyl group of the epoxy compound at the time of charging / the equivalent of the alkoxyl group of the alkoxysilane condensate (B) (equivalent ratio) = 0.068, and the epoxy equivalent was 83.
It is 2 g / eq.

Synthesis Example 3 (Production of Alkoxy Group-Containing Silane-Modified Polyimide Resin Composition (A)) N-methylpyrrolidone was placed in a 2 L 4-necked flask equipped with a stirrer, a cooling tube, a thermometer and a nitrogen gas introducing tube. While charging and cooling to 40 ° C. or lower, 4,4′-diaminodiphenyl ether and pyromellitic acid were added so that (the number of moles of tetracarboxylic acid) / (the number of moles of diamine) = 0.99, and 40 ° C. To react for 1 hour to obtain a polyamic acid solution. Then, the temperature was raised to 90 ° C. over 1 hour to carry out a dehydration ring closure reaction to obtain a polyimide (2A). I
When analyzed using R, the imide ring closure rate was 25%. The polyimide (2A) solution is heated to 80 ° C., and the epoxy group-containing alkoxysilane partial condensate (3A) is added.
(Equivalent weight of epoxy group of epoxy group-containing alkoxysilane partial condensate (3)) / (Equivalent weight of carboxylic acid group of tetracarboxylic acid used in polyamic acid (1) and / or polyimide (2)) = 0.07 In addition to 80 ℃
And reacted for 16 hours. Cool to room temperature and leave a cure residue of 17
% Alkoxy group-containing silane-modified polyimide (A-1)
A solution was obtained.

Synthesis Example 4 (Production of Alkoxy Group-Containing Silane-Modified Polyimide Resin Composition (A)) The polyimide (2A) solution obtained in Synthesis Example 3 was heated to 80 ° C. to obtain an epoxy group-containing alkoxysilane partial condensate (3
B) is the (epoxy group equivalent of epoxy group-containing alkoxysilane partial condensate (3)) / (polyamic acid (1)
And / or the equivalent of the carboxylic acid group of the tetracarboxylic acid used in the polyimide (2)) = 0.10, reacted at 80 ° C. for 14 hours, and then cooled to room temperature,
An alkoxy group-containing silane-modified polyimide (A-2) solution having a curing residue of 17% was obtained.

Synthesis Example 5 (Production of alkoxy group-containing silane-modified polyimide resin composition (A)) N-methyl-2-pyrrolidone was placed in a reaction vessel equipped with a stirrer and a nitrogen inlet tube in the same apparatus as in Synthesis Example 3. Was further added, and paraphenylenediamine and 3,3 ′, 4,4′-biphenyltetracarboxylic acid anhydride were added so as to have a ratio of 0.99, and the mixture was reacted for 1 hour to obtain a polyamic acid (1A). When analyzed using IR, the imide ring closure rate was 0.
%Met. The polyamic acid (1A) solution was heated to 80 ° C., and the epoxy group-containing alkoxysilane partial condensate (3
A) is the (epoxy group equivalent of the epoxysilane-containing alkoxysilane partial condensate (3)) / (polyamic acid (1)
And / or the equivalent amount of the carboxylic acid group of the tetracarboxylic acid used for the polyimide (2) = 0.07, and reacted at 80 ° C. for 16 hours. After cooling to room temperature, an alkoxy group-containing silane-modified polyimide (A-3) solution having a curing residue of 17% was obtained.

Production Examples 1 to 3 The alkoxy group-containing silane-modified polyimide solutions of Synthetic Examples 3 to 5 were sequentially processed into silane-modified polyimide resin compositions (1) to
(3).

Production Example 4 (Production of Silane-Modified Polyimide Resin Composition (B)) The alkoxy group-containing silane-modified polyimide (A-1) solution obtained in Synthesis Example 4 was mixed with silica filler (manufactured by Tokuyama Corp.).
Trade name Fineseal T-32: Average particle size 1.5μ
m) is an alkoxy group-containing silane-modified polyimide (A-
1) 30 wt% of the curing residue of the solution was mixed and sufficiently stirred with a mixer to obtain a silane-modified polyimide resin composition (4).

Comparative Production Example 1 (Production of Silane-Modified Polyimide Resin Composition) Polyimide varnish (trade name: Pyr, manufactured by IST Co., Ltd.)
e-ML: monomer composition, pyromellitic dianhydride, 4,
4′-diaminodiphenyl ether, solvent: N-methylpyrrolidone, polyimide curing residue: 15%) were used as they were to obtain a polyimide resin composition (H-1).

Comparative Production Example 2 (Production of Silane-Modified Polyimide Resin Composition) The polyamic acid (2A) obtained in Synthesis Example 5 was used as it was to obtain a silane-modified polyimide resin composition (H-2).

[0052]

[Table 1]

(Thermal Expansion Property) The silane-modified polyimide resin compositions of Production Examples 1 to 4 and the polyimide resin compositions obtained in Comparative Production Examples 1 and 2 were cast on a tin plate to give 120
After drying at ℃ for 20 minutes, peel off from the tin plate, 2
After curing at 50 ° C. for 20 minutes, a polyimide-silica hybrid film having a film thickness of 25 μm and a polyimide film were obtained. Thermal stress strain measurement device (TM manufactured by Seiko Denshi Kogyo)
A120C), the linear expansion coefficient of 40-200 degreeC was measured. The results are shown in Table 2.

[0054]

[Table 2]

Example 1 (Production of Metal Laminate) A silane-modified polyimide resin composition (1) was used as an electrolytic copper foil (manufactured by Furukawa Electric Co., Ltd. under the trade name “FO-WS”, film thickness 18).
μm, surface roughness Rz = 1.5) was applied with a # 75 bar coater, dried at 120 ° C. for 20 minutes and then cured at 360 ° C. for 10 minutes to obtain a metal laminate having a polyimide film thickness of 25 μm. .

Examples 2 to 4, Comparative Examples 1 and 2 (Production of Metal Laminates) Instead of the silane-modified polyimide resin composition (1), silane-modified polyimide resin compositions (2) to (4) and polyimide in this order. A metal laminate having a polyimide film thickness of 25 μm was obtained in the same manner as in Example 1 except that the resin compositions (H-1) and (H-2) were used.

Example 5 (Production of Metal Laminate) A metal laminate having a polyimide film thickness of 5 μm was obtained in the same manner as in Example 1.

Example 6 (Production of Metal Laminate) In the same manner as in Example 1, a silane-modified polyimide resin composition (1) was cast on a copper foil and dried at 120 ° C. for 20 minutes to obtain a polyimide. The polyimide resin composition (H-2) was cast on the polyimide resin side of the metal laminate having a film thickness of 6 μm, dried again at 120 ° C. for 20 minutes, and cured at 360 ° C. for 10 minutes to obtain a total of two polyimide layers. Has a film thickness of 26
A metal laminate having a thickness of μm was obtained.

Example 7 (Production of Metal Laminate) In the same manner as in Example 1, a silane-modified polyimide resin composition (1) was cast on a copper foil and dried at 120 ° C. for 20 minutes to obtain a polyimide. The silane-modified polyimide resin composition (4) was cast on the polyimide resin side of the metal laminate having a film thickness of 6 μm, and dried again at 120 ° C. for 20 minutes.
It was cured at 60 ° C. for 10 minutes to obtain a metal laminate having a total film thickness of 25 μm of two polyimide layers.

Comparative Example 3 In the same manner as in Example 1, a polyimide resin composition (H-
1) is cast on a copper foil and dried at 120 ° C. for 20 minutes, and a silane-modified polyimide resin composition (4) is provided on the polyimide resin side of the metal laminate having a polyimide film thickness of 6 μm.
Cast, dried again at 120 ° C for 20 minutes, 360 ° C
After curing for 10 minutes, the total thickness of the two polyimide layers is 2
A metal laminate having a thickness of 6 μm was obtained.

(Adhesion) Metal foil laminates (1-7) of Examples 1-7 and metal foil laminates (H- of Comparative Examples 1 and 2)
No. 1, H-2) was subjected to a goggles cellophane tape peeling test according to the general test method of JIS K-5400, and judged according to the following criteria. The evaluation results are shown in Table 3. ⊚: 100/100 ◯: 99 to 90/100 Δ: 89 to 50/100 ×: 49 to 0/100

(Smoothness) The metal foil laminates of Examples 1 to 7 (1 to 7) and the metal foil laminates of Comparative Examples 1 and 2 (H-
1, H-2) was visually evaluated for smoothness. The evaluation results are shown in Table 3. ◯: There is no warp. Δ: Warpage is seen. X: Curled.

(Solder Heat Resistance) Metal foil laminates (1-7) of Examples 1 to 7 and metal foil laminates (H- of Comparative Examples 1 and 2).
1, H-2) was immersed in a solder bath at 300 ° C. for 10 minutes, and the presence or absence of foaming was evaluated. The evaluation results are shown in Table 3. ◯: Good without foaming. △: Partially foamed ×: Foamed on the entire surface

(Heat Resistance Adhesion) The metal foil laminates (1-7) of Examples 1 to 7 and the metal foil laminates (H- of Comparative Examples 1 and 2).
1, H-2) is immersed in a solder bath at 300 ° C. for 10 minutes and then left to cool for 10 minutes. This operation was repeated 10 times and the adhesion was evaluated. The evaluation results are shown in Table 3. ⊚: No change in appearance, no change in adhesiveness before and after immersion in solder bath ◯: Swelling occurs and adhesiveness decreases. X: The laminate peeled off during immersion in the solder bath.

[0065]

[Table 3] In Table 3, in the polyimide composition column of Example 6, (1)
→ (H-2) is a silane-modified polyimide resin composition (1)
After casting, further polyimide resin composition (H-2)
Indicates to cast. Example 7 and comparative example 3 have the same meaning.

(Plating Adhesion) Examples 1, 3, 4, 7,
The metal foil laminates of Comparative Examples 1 and 2 are sequentially subjected to conditioner treatment, micro etching, pickling, catalysis, and accelerator treatment, and electroless copper plating is performed to 0.3 μm.
A thin copper plating was applied to the surface. The polyimide resin side of the metal foil laminate thus obtained was further electroplated to have a conductor thickness of 30 μm, and the peel strength was measured according to JIS C 6481. The evaluation results are shown in Table 4.

[0067]

[Table 4]

Example 8 (Production of Metal Laminate) A silane-modified polyimide resin composition (1) was used as an electrolytic copper foil (manufactured by Furukawa Electric Co., Ltd. under the product name “FO-WS”, film thickness 18).
μm, surface roughness Rz = 1.5) was applied with a # 36 bar coater, dried at 120 ° C. for 20 minutes, and then cured at 360 ° C. for 10 minutes to obtain a metal laminate having a polyimide film thickness of about 15 μm. It was

Examples 9, 10, Comparative Examples 4 and 5 (Production of Metal Laminate) Instead of the silane-modified polyimide resin composition (1), silane-modified polyimide resin compositions (2), (3) and polyimide A metal laminate having a polyimide film thickness of about 15 μm was obtained in the same manner as in Example 1 except that the resin compositions (H-1) and (H-2) were used.

(Copper Ion Migration) Example 8
10 and the metal foil laminates of Comparative Examples 4 and 5 at room temperature and humidity of 9
It was left still for 3 days in a state of 5%. The imide surface of the metal foil laminate was measured with an X-ray photoelectron spectrometer (manufactured by Shimadzu Corporation, trade name “ESCA-3200”) at a voltage of 0.6 ke.
The imide surface subjected to argon ion etching for 5 minutes at a current value of 50 mA for V was subjected to surface analysis under the conditions of a voltage of 10 KV, a current of 30 mA, and an integration number of 3 times. Further, the surface etching / surface analysis was repeated until the copper atoms derived from the copper foil (zero valence) appeared. In the metal foil laminates of Examples or Comparative Examples, the imide layer disappeared after etching for a total of 200 to 250 minutes, and copper atoms derived from copper foil appeared. The migration was evaluated by determining the copper ion (divalent) concentration with respect to carbon atoms in the imide layer 2 μm from the copper foil surface.

[0071]

[Table 5] As is clear from Table 5, copper ions were detected in the metal foil laminates of Comparative Examples 4 and 5, and copper migration was confirmed. On the other hand, in Examples 8 to 10, the copper ion concentration was lower than in Comparative Examples 4 and 5, and it was found that the migration resistance was excellent.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F100 AA01A AB01B AB33B AK49A                       AL05A AL08A BA02 CA23                       EH46 EH462 EJ08 EJ082                       EJ86 EJ862 GB41 JA02A                       JL11 YY00A                 4J002 CM041 CP181 DE076 DE136                       DE146 DE186 DE236 DG046                       DG056 DH046 DJ006 DJ016                       DJ036 DJ046 FD016 GF00                       GQ01 HA05                 4J043 PA02 PA19 PC195 PC196                       QB15 QB26 QB31 RA35 SA06                       SA07 SA42 SA44 SA54 SA55                       SA61 SB01 TA11 TA12 TA13                       TA21 TA22 TB01 TB02 UA032                       UA041 UA122 UA131 UA132                       UA141 UA151 UA152 UA251                       UA261 UA262 UA711 UB011                       UB012 UB021 UB022 UB051                       UB061 UB062 UB121 UB122                       UB131 UB132 UB152 UB281                       UB301 UB302 VA011 VA041                       VA042 VA051 VA081 VA082                       XA16 XA19 YA06 YA08 YB08                       YB40 ZA23 ZB50

Claims (5)

[Claims] 1. An alkoxy group-containing silane-modified polyimide (a) obtained by reacting a polyamic acid (1) and / or a polyimide (2) with an epoxy group-containing alkoxysilane partial condensate (3), and a polar solvent (b). A metal foil laminate obtained by casting a silane-modified polyimide resin composition (A) containing a) on a metal foil. 2. An alkoxy group-containing silane-modified polyimide (a) obtained by reacting a polyamic acid (1) and / or a polyimide (2) with an epoxy group-containing alkoxysilane partial condensate (3), a polar solvent (b). ) And a silane-modified polyimide resin composition (B) containing an inorganic filler (c) are cast on a metal foil to obtain a metal foil laminate. 3. An alkoxy group-containing silane-modified polyimide (a) obtained by reacting a polyamic acid (1) and / or a polyimide (2) with an epoxy group-containing alkoxysilane partial condensate (3), and a polar solvent (b). ) Containing a silane-modified polyimide resin composition (A) is cast on a metal foil, and then a resin composition containing a polar polymer (b) and a polyimide polymer that forms a film having a linear expansion coefficient of 25 ppm or less. The metal foil laminated body obtained by doing. 4. An alkoxy group-containing silane-modified polyimide (a) obtained by reacting a polyamic acid (1) and / or a polyimide (2) with an epoxy group-containing alkoxysilane partial condensate (3), and a polar solvent (b). Obtained by casting a silane-modified polyimide resin composition (A) containing a) on a metal foil and then casting a silane-modified polyimide resin composition (A) which forms a cured film having a linear expansion coefficient of 25 ppm or less. Metal foil laminate. 5. A double-sided metal foil laminate obtained by plating the polyimide resin side of the metal foil laminate according to claim 1.